Decoding relay system



Dec. 11, 1945. F. x. REES DECODING RELAY SYSTEM Filed Dec. 17, 1942 2 SheetsSheet 1 (Iltotneg Dec. 11, 1945. FL x R E 2,390,666

DECODING RELAY SYS TEM Filed Dec. 17, 1942 2 Sheets-Sheet 2 FIG.4.

H i L JL F 70 H) c L F u i 3 c 1 71 7AM; Mam

w Cittorneg Patented Dec. 11, 1945 DECODING RELAY SYSTEM Frank X. Rees, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application December 17, 1942, Serial No. 469,346

10 Claims.

This invention relates in general to relays particularl adapted for railwa use, and has more specific reference to a direct current. relay for use in decoding the impulses employed in code-d type signalling systems for railroads.

In the conventional coded track circit for railroads, codes of different rates are applied at one end of the track circuit in accordance with traffic conditions, while a code following track relay at the opposite end of the track circuit acts on suitable decoding apparatus which indicates the different distinctive code conditions. Usually this decoding apparatus comprises means distinctively controlled in accordance with whether or not there is any code reception, as well as other means distinctively controlled in accordance with the particular distinctive code then being received. The first mentioned means distinguishing whether or not a code is being received, sometimes comprises a decoding transformer having a primary winding controlled by the code following track relay with the secondary winding acting on a home relay of the slow-acting neutral type through rectifying contacts on the code following track relay in a manner similar to that shown in the Patent No. 2,291,579, granted July 28, 1942, to T. J. Judge.

The present invention contemplates a simplification of the above mentioned conventional decoding means by the. provision of a novel relay to act as a home rela directly controlled by the code following track relay. This novel relay contemplated by the present invention comprises what ma be termed as a split core structure, each branch of the core having a control winding which is rendered effective to produce a magnetic flux to act on the relay armature only providing that such winding is only momentarily energized. In other words, the relay armature is caused to be picked up and remain picked up only providing the windings for the two core branches are alternately energized by the operation of the code following track relay, but if the operation of the code following track relay ceases and a single winding of the relay is steadily energized, the armature thereof immediatel drops away. Although the present invention is contemplated as being particularly useful in connection with coded track circuits for railroads, as above mentioned, it is believed that it may also be useful in other connections such as with train control and the like.

Other objects, purposes and characteristic features of the present invention will be in part; obvious from the accompanying drawings, and in.

part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to. the accompanying drawings, in which like reference characters designate corresponding parts throughout the several views, and in which:

Fig. 1 is a side elevation of, the relay .of' the present invention with parts shown. in section to more clearly bring out the. features of the present invention;

Fig. 2 is a to plan view of the relay shown in Fig. l I

Fig. 3 is a fragmentary view showing a detail of the core and armature structure of, the relay of l and 2 viewing such relay from the left with respect to Fig. 1, and with certain parts shown in section to more clearly bring out the characteristics of the novel structure;

Fig. 4 is a diagrammatic illustration of the. relay and simplified control circuits therefor showing the relay in an operated position; and

Fig. 5 is a diagrammatic illustration of the relay and its simplified control circuits showing the relay in a non-operated position.

Referring now to Fig. l of the drawings, the relay comprises a top plate 5 of suitable insulating material to which is connected a casing 8, prefer ably of glass or other transparent material. These two members are held together by two bolts 1 which extend downwardly through the casing 5 on opposite sides of the contact structure within the casing 6. The heads of these bolts 1 can be seen in Fig. 2. Each of these bolts 1 has an insulating tube 2 mounted thereon and held in position by lock nuts 3. Suitable keyed nuts 8 hold the casing 6 against the top plate 5 with a suitable gasket 9 located between the members 5 and 6 to provide a water-tight relationship.

The top plate 5 serves as a mounting for a core and armature structure as well as the various binding posts which are provided for the electrical connections to the contact structure operated by the armature structure. In this connection, it will be noted that the binding posts for providing electrical connections to the control windings of the relay are supported b the core structure in a manner presently to be described.

The core structure comprises two short poleface pieces I!) and l l respectively held in position by look nuts I2 and 4 to which the control portion of the core is attached. This control portion of thecore includes a U-shaped coil mounting core piece l3 connected to the rear pole-face piece I0 by a notched fiatefaced joint as best shown in Figs. 1 and 2 by the dotted lines, being held together by a bolt [4 and cooperating nut l5.

A coil supporting member 16 of fiber, formica or like insulating material, is slipped over the upwardly extending branches or arms of the coil mounting core piece l3 and rests on the inner base of this U-shaped member. Coils I1 and [8 are positioned respectively on the two branches of the U-shaped core piece 13 with protective fiber Washers l9 so that the upper ends of. the two branches of the U-shaped core piece I3 may be connected by cross-bar members and 2|. These cross-bar members join the two branches of the U-shaped piece l3 by notched fiat-faced joints and are held in position by the bolts 22 and 23 with their respective cooperating nuts 24 and 25.

These bolts 22 and 23 also connect L-shaped members 26 and 21 to the cross-bar member 2| so as to provide a magnetic circuit to the forward core upright which includes a top piece 28, and a bolt 29 of suitable magnetic material. I

The bolt 29 serves as a mounting for conventional rectifier discs which are placed over the bolt 29 and compressed into positions in which 2 they are held by lock nuts 39. This rectifier structure includes two rectifier units R and R. separated by an insulated spacer 3| with each rectifier having its own terminals numbered 32, 33, 34and 35. any suitable type, such as shown for example in the Patent No. 1,640,335 dated August 23, 1927. The rectifier units, being of the so-called copper oxide type, include copper discs as well as other discs and spacers making up the respective units as more specifically described in the above mentioned Patent No. 1,640,335. The rectifier units of course have the usual characteristics, that is, current will flow through the unit in one direction while current flow is prevented in the opposite direction through that unit. The various discs comprising the rectifier units are of course insulated from the bolt 29. In other words, the rectifier units are constructed in the conventional manner, the bolt 29 being of magnetic material and acting as a portion of the magnetic core structure. It should also be understood that the copper discs employed for these rectifier units not only act as parts of asymmetric electrical units, but also act as the usual copper slugs provided on the core structure of a direct current relay to render its magnetic structure slowacting with respect to magnetic flux build-up and magnetic fiux decay.

These rectifier units are located in the midportion of the bolt 29 so that one end of the bolt is threaded into the fcrward pole-face piece H while top core piece 28 is threaded onto the upper end of the bolt 29 to a proper position between the L-shaped members 26 and 21 and brought into firm contact therewith by a bolt 38 and cooperating nut 31. The top core piece 28 is of course round but it is provided with fiat surfaces at the upper end so as to make flat surfaced contact with the L-shaped core members 26 and 21.

The bolt 36 also holds in position the terminal block 38 by a suitable T-shaped mounting member 39 which extends to the left of the bolt 36 as viewed in Figs. 1 and? with protruding edges 48 that overlap the L-shaped member 21 in a manner to provide a firm support for the block 38. This block 38 has suitable binding posts for connections to the rectifier units and the coils l and I8 as will be described more in detail hereinafter.

With reference to Fig. 3 of the acco p y These rectifier units may be of 'tacts 63 and fixed back contacts 64.

drawings, it will be seen that an armature support member 50 is attached to the top plate 5 by bolts 5! upon which look nuts 52 may be suitably positioned so as to bring the armature 53, as supported on bearing members 54 attached to the armature by set screws 55, into an exact, parallel position with the core pole-faces and having the desired air gap. The forward end of the armature 53 is of course provided with aresidual pin 56 of suitable non-magnetic material.

Mounted to the armature member 53 by suitable lock nuts and insulating spacers 6| are suitable contact fingers 60. The contact fingers may be of any suitable type such as shown in Patent No. 1,748,918 dated February 25, 1930, or Patent No. 1,824,129 dated September 22, 1931; While the spacer mountings 6| may be of the type shown Patent No. 2,217,229 dated October 8, 1940, or any other suitable arrangement It is contemplated that two of these articulated contact fingers 69 cooperate with their respective fixed front con- While the front contacts 63 are held to the casing 5 by their respective binding posts. the back contacts 64 are held in position by a U-shaped structure having two downwardly extending metal legs 62 connected at the top to their respective binding posts and interconnected atlthe bottom by an insulating spacer member 65 forming the enclosed portion of the U-shaped structure. The two back contacts 64 are connected to the respective metal legs 62. It is to be understood that the relay may be designed for operation with any desired number of such contact fingers 60.

With reference to Fig. 4, it will be seen that a diagrammatic illustration of the relay is provided. This illustration is not to'be considered an actual structural illustration inasmuch as the U- shaped core piece I3 is actually located at right angles to the U-shaped core structure as a whole but in the illustration f Figs. 4 and 5, it is convenient to distort such structure for the purpose of indicating the passage of magnetic fiux through the co e and armature structures. 7

In Fig. 4, th'e rectifier units R and R are diagrammatically indicated as connected across the terminals of their respective coils l1 and I8, it being understood that these rectifier units are actually on the forward portion of the core structure as shown in Fig. 1 and indicated in Figs. 4 and 5 by the dot-dash lines which are also given the reference charactezs R and R These units R and R have thus been indicated in these diagrammatic figures because they have the dual purpose of acting as asymmetric units and as short-circuited windings (or sometimes called copper slugs). V

In Fig. 4, a code following relay CF is assumed to be steadily operating at some given code rate. While the contacts 10 and H of this code following relay are in their lower positions, a circuit is closed from through a circuit including back contact 10 of relay CF, winding I'I, back contact H of relayCF, to The current which fiows in this circuit cannot be shunted by the rectifier unit R because of the relative polarity with which it is connected across the coil 11, This energization of the coil l1 causes magnetic flux to flow upward through its associated branch of the core structure as indicated by the arrows associated therewith. a

Similarly,-when the contacts of the code following relay are in their opposite positions, a circuit is closed from through a circuit including front contact 10 of relay CF, winding l8, front a,seo,eee

contact II of relay CF, to The current which'fiows throughthe coil l 8 cannot be shunted by the rectifier unit R because of the relative polarity with which it is connected into the circuit. The current which flows through the coil It! causes a magnetic flux to flow upwardly through the left-hand branch of the U-shaped core structure in a direction indicated by the arrows associated therewith.

The initial energization of the coil I1 causes a magnetic flux to move upward in its branch of the core structure, while the preceding deenergization of the coil l8 resulting in the decay of magnetic flux in its branch tends to continue such magnetic flux due to the fact that the self-induced E. M. F. produced in the coil by such. decay is shunted by the rectifier unit R Thus, the flux which is maintained in the left-hand branch of the core structure by this short-circuited winding l8 opposes the magnetic flux produced by the initial current flow in the coil I! so that a flux movement is produced in a clockwise direction 'viewed in Fig. 4 throughout the core structure and including the armature 53. As the flux deoays in the left-hand branch of the core structure any rise of flux therein in the opposite direction is retarded because any rise of flux in such branch in an opposite direction produces a selfinduced E. M. F. in the coil [8 which is shunted by the rectifier unit R thus producing a choking effect on any flow of flux through the lefthand branch as produced by the energization of the coil [1. This means that magnetic flux must flow through the right-hand branch and the remaining portion of the core and armature structures for a limited period of time after the initial energization of the coil l1.

Similar operation is also present upon the initial energization' of the coil I8 with the contacts 70 and H in their operated or picked up positions. This will not be recited in detail as such operation will be understood by analogy to that just given. Thus, the continued operation of the contacts 10 and H acts to alternately energize the coils H and I8 which produces a flux flowing through the core and armature structure to maintain the armature 53: in an operated position.

However, if the contacts I and H remain either in an operated position or in an unoperated position one or the other of the coils I! and I8 is energized steadily, and this steady energization of a particular coil of course stabilizes the flux condition in the U-shaped core structure 13 so that the opposite coil and its associated rectifier unit then ceases to have a choking effect and allows the flux produced by said particular coil to be short-circuited without flowing through the core and armature structures (see Fig. This of course causes the armature 53 to drop away due to its biasing force supplied by gravity in this case. This biasing force is of course accentuated by the additional force of the front contact spring pressure. In this way, the continued operation of the code following relay CF Within a certain range of code rates maintains the armature 53 picked up so that the contact fingers may close their front contacts to complete control circuits as desired; while the cessation of the code following relay CF in either position or the reduction of its operation to a very low rate of operation will result in the dropping away of the armature for closing its associated back contacts to complete such control circuits as may be desired. It is noted that the copper discs of the rectifier units R and R and their copper compressing end washers 43 mounted on the forward core portion act to provide a slow-releasing effect upon the armature 53 between the successive impulse energizations of the coils I1 and [8. This maintains the armature 53 in a picked up position between such impulses. In other words, the rectifier units R and R serve several useful purposes.

In this connection, it should be understood that the rectifier units R and R do not necessarily have to be mounted on the core structure in order to practice the present invention. For example, these rectifier units R and R may be mounted separately, but connected to the coils I1 and IS in the same manner as disclosed. Then, in order to cause the relay to be slow-acting, that is, maintain its armature 53 picked up between successive impulses, the usual copper discs or slugs may be placed on the forward core member. In such a case the pole-face member H (see Fig. 1) would probably be lengthened so as to extend to the L-shaped members 26 and 21. In other words, the forward core member need be made in parts only if the rectifier units R and R are to be mounted thereon.

With reference to Fig. 5, the arrows which indicate the shunted flux condition with respect to the magnetic flux produced by the steady energization of coil I1, for example, indicate that there is an entire absence of flux in the remaining core structure. Actually there will probably be a'certain amount of fiux through the core and armature structures due to the reluctance of the opposite branch, but this amount will be of a relatively small value and will not operate the armature 53. Furthermore, this flux which may pass through the core and armature will vary in amount in accordance with the degree of saturation of the core structure at which the relay is operated. Also, this leakage flux will depend upon the relative amounts of iron in the branched core structure I3 as compared to the remaining portions of the magnetic circuit including the armature 53. But in any event the armature 53 remains dropped away unless its coils are impulsed. In this connection, it is again desired to point out that the operation is symmetrical, and the armature 53 drops regardless of whether the coil. H or the coil 18 is steadily energized.

The U-shaped core piece l3 employed for mounting the coils i1 and I8, is preferably of a single piece of magnetic material bent to conform with the shape required for the desired construction of the relay. This method of forming this core piece l3 not only simplifies the physical manufacture of such piece, but also provides that the magnetic properties of the two branches of the core are more nearly alike. Although a relay may be constructed in accordance with this invention using separate pieces of magnetic material for the two branches, some difiiculty might be experienced in providing two pieces of core material which would have substantially identical magnetic properties. Thus, although a certain unbalance in magnetic properties may be tolerated in the branched core structure, it is desirable for the best operation of such a relay to have the magnetic properties of the two branches substantially the same.

This novel relay structure and associated control circuit organization operates to provide decoding apparatus that distinctively responds to the presence of codes but assumes a normal biased position upon the cessation of suchcodes; and, this organization is believed to be a substantial simplification of the usual organization required for such purposes as mentioned heretofore especially since this organization is a unitary piece of apparatus which may be directly connected to code following relays.

Having described a relay structure and control circuit arrangement as one specific embodilimit the number of forms which it may assume;

and, it is to be further understood that various modifications, adaptations and alterations may be made to the specific form shown to meet the requirements of practice, Without in any manner departing from the spirit or scope ofthe present invention except as limited by the appended claims.

What I claim is:

1. In an electro-magnetic relay, a U-sh'aped core structure one leg of which is divided into bifurcated portions and th other leg of which has mounted thereon short-circuited windings, two operating windings one on each bifurcated portion, and two asymmetric means, each for shunting its respective one of said operating windings.

2. In an'electro-magnetic relay, a U-shaped core structure one leg of which is divided into bifurcated portions forming a closed magnetic circuit and the other leg of which includes the magnetic core of two rectifier units comprising copper discs and their cooperating spacer discs, operating windings one on each bifurcated portion, a cooperating armature associated with'the open end of said U-shaped core structure, and circuit means for connecting said rectifier units across the respective operating windings, whereb-ysaid rectifier units act to short-circuit current flow in one direction through the respective operating windings but not in the other direction, while at the same time acting to render the core structure slow-acting with respect to magnetic flux changes in said cooperating armature.

3: In a relay structure, a U-shaped core member having closed bifurcated portions, a movable armature cooperating with said core, a separate winding on each bifurcated portion, and an asymmetric unit connected across each winding, whereby alternate energization of said windings causes magnetic flux to act on said armature but the flux produced by steady energization by either winding is shunted away from said armature.

4. In a relay structure, a core structure having two pole-face pieces and including two parallel connected branches of magnetic material between said pole-face pieces, a movable armature associated with said pole-face pieces, two operating windings one on each of said branches, and a rectifier unit so connected in multiple with each winding that the alternate energization of said windings causes said armature to be picked up while the steady energization of either winding does not act on said armature.

5. In an electro-magnetic relay, a U-shaped core structure one leg of which includes two parallel branches to form a closed magnetic circuit, said two branches being constructed of a 7 single piece of magnetic material, whereby said two branches have substantially identical magnetic characteristics, a pivoted armature adjacent the open end of said U-shaped core structure, a separate winding on each branch of said one leg, copper discs mounted on the other leg of said core structure, and asymmetric circuit means for shunting each of said windings, where- 1 by said armature is maintained in'its operated position by the alternate energization of said windings but is released when either of said windings is steadily energized.

6. In an electro-magnetic relay, a U-shaped core structure one leg of which is divided into closed bifurcated portions, a pivoted armature adjacent the open end of said U-shaped core structure, a separate winding oneach bifurcated portion, circuit means for at times energizing said windings alternately and at other times steadily energizing one or the other of said windings, said circuit means being so connected to said windings as to produce magnetic flux in the same direction through said bifurcated portions, and means associated with each bifurcated portion tending to prevent the rapid change in flux in its bifurcated portion, whereby said armature is picked up when said windings are alternately energized but is dropped away when'either winding is steadily V energized.

7. In an electro-magnetic relay, a U-sh'aped core structure, a pivoted armature associated with the open end of said U-shaped core structure, an operating winding on said core structure for producing magnetic flux therein when energized so as to actuate said armature to an operated position, a portion of magnetic material for shunting the flux produced by said operating winding to prevent its flow through said armature, means associated with said portion tending to prevent fluxchange therein, and a rectifier unit connected in multiple with said operating winding in such a manner as to shunt any selfinduced F. generated in said operating winding'but failing to shunt the proper energization of said operating winding.

8. In combination, an electro-mag'netic structure including a core having a bifurcated portion and a cooperating armature, an operating winding mounted on each of said bifurcated portions, an asymmetric unit for shunting each of said operating windings with respect to any self-induced E. M, F. produced in such windings, and 7 which includes two parallel branch portions forming a closed magnetic circuit and the otherleg of which has short-circuited windings mounted thereon, an operating winding for each of said branch portions, a cooperating armature associated with the open end of said U-shaped core structure, and asymmetric means connected in multiple with each of said operating windings, and circuit means for causing said operating winding to be alternately energized up n the operation of said coding contacts to their opposite positions.

10. In an electromagnetic relay structure, a base plate of insulating material, two pole-face pieces extending through said base plate with the faces of said pieces beneath said base plate, a pivoted armature located beneath saidbase plate and adapted to cooperate with said pole-face pieces, a U-shaped core structure above said base plate and interconnecting said two pole-face pieces,one leg of said core structure including two cuited causes magnetic flux to pass through said armature because each winding short-circuited by its respective rectifier acts to prevent magnetic flux changes in its parallel branch when the other winding is energized, and whereby said armature is maintained picked up between the successive and alternate energizations of said two operating windings by reason of the holding efiect of said copper discs of the rectifier units but is dropped away by the steady energization of either operating winding.

FRANK X. REES. 

